The purpose of this research project is to identify viral markers and develop rapid quantitative methods for 1) detecting and quantifying low levels of infected HIV in blood and blood products, 2) estimating viral burden in clinical material, 3) characterizing virus target cells and 4) distinguishing among various virus strains. Rapid assays for the detection of infectious virus were developed based on reverse transcriptase activity and the indicator T-cell line, H-938. A monocytic indicator cell line was tested for its possible utility in detecting HIV virus in saliva, plasma and PBL's (see "Salivary inhibitor(s) may cause low viral recovery from saliva samples in vitro," Qureshi, Henrard, Joshi, Geyer, Hewlett, Qiu, Lopez and Barr. Abstract presented at October 18-20, 1993 meeting of the American Society of Clinical Pathologists in Orlando, FL). Results indicated that the monocytic cell line supported a single cycle of viral replication which was not useful for detecting extremely low quantities of infectious virus in human tissue samples. Work is continuing to develop an equally sensitive, but non-radioactive, method for monitoring the response of indicator T-cell line to HIV infection.